NAME
Crypt::OpenSSL::Random - Routines for accessing the OpenSSL pseudo-random number generator using the openSSL libraries
SYNOPSIS
use Crypt::OpenSSL::Random;
Crypt::OpenSSL::Random::random_seed($good_random_data);
Crypt::OpenSSL::Random::random_egd("/tmp/entropy");
Crypt::OpenSSL::Random::random_status() or
die "Unable to sufficiently seed the random number generator".
my $ten_good_random_bytes = Crypt::OpenSSL::Random::random_bytes(10);
my $ten_ok_random_bytes = Crypt::OpenSSL::Random::random_pseudo_bytes(10);
DESCRIPTION
Crypt::OpenSSL::Random provides the ability to seed and query the OpenSSL library's pseudo-random number generator.
EXPORT
None by default.
Static Methods
- random_bytes (IV num_bytes)
-
This function, returns a specified number of cryptographically strong pseudo-random bytes from the PRNG. If the PRNG has not been seeded with enough randomness to ensure an unpredictable byte sequence, then a false value is returned.
- random_pseudo_bytes (IV num_bytes)
-
This function, is similar to c<random_bytes>, but the resulting sequence of bytes are not necessarily unpredictable. They can be used for non-cryptographic purposes and for certain purposes in cryptographic protocols, but usually not for key generation etc.
- random_seed (PV random_bytes_string)
-
This function seeds the PRNG with a supplied string of bytes. It returns true if the PRNG has sufficient seeding. Note: calling this function with non-random bytes is of limited value at best!
- random_egd (PV egd_string)
-
This function seeds the PRNG with data from the specified entropy gathering daemon. Returns the number of bytes read from the daemon on success, or
-1
if not enough bytes were read, or if the connection to the daemon failed. - random_status ()
-
This function returns true if the PRNG has sufficient seeding.
BUGS
Because of the internal workings of OpenSSL's random library, the pseudo-random number generator (PRNG) accessed by Crypt::OpenSSL::Random will be different than the one accessed by any other perl module. Hence, to use a module such as Crypt::OpenSSL::Random, you will need to seed the PRNG used there from one used here. This class is still advantageous, however, as it centralizes other methods, such as random_egd
, in one place.
AUTHOR
Ian Robertson, iroberts@cpan.com
Now maintained by Reini Urban, rurban@cpan.org
LICENSE
This module is available under the same licences as perl, the Artistic license and the GPL.
SEE ALSO
perl(1), rand(3), RAND_add(3), RAND_egd(3), RAND_bytes(3).